Many liquid or semi-liquid products have been packaged in bottles or other containers provided with dispensing valves or nozzles from which quantities of the material can be dispensed when desired, the valves usually providing for both "open" and "closed" positions.
Most of the dispensing closures or valves which previously have been suggested consist of two or more pieces one of which must be manually moved relative to the other in order to open the valve. This requires that the user hold the container in one hand and open the valve member with the other hand.
In addition, manufacture of two-part dispensing valves or closures requires that two separate mold cavities be designed and employed, one for each of the two parts and that these parts be assembled to each other either manually or by assembly machinery before they are attached to the respective containers. The cost of these two-part valves or closures is therefore increased by the necessity for amortizing the cost of the two separate molds and the cost of the manual assembly or the assembly machine.
Examples of the closures or valves of the type just discussed are shown in Collins U.S. Pat. No. 2,901,153 and Hazard U.S. Pat. No. 4,081,113. Although the dispensing valve of 2,901,153 is shown as being in place in the lid of a can-like container 14, similar dispensing valves are also provided in screw-on or snap-on caps for other types of containers. While the closure of U.S. Pat. No. 4,081,113 is shown as also having a so-called "child resistant" feature, similar dispensing closures without the child resistant feature have been utilized on many containers for products as different as cigarette lighter fluid, charcoal igniting fluid, hand cream, dishwashing liquids, etc.
It is customary for the manufacture of such a closure to assemble them in "closed" condition and to ship them to the organization which fills the containers so that they can be placed on the containers after they are filled by the use of automatic capping machinery. As a result, of course, the cost of assembling the two pieces of two-part closures or valves must be borne by the manufacturing company and included in the cost to their customer.
From the standpoint of the final user, for example, a housewife, it would be preferable if the closure or valve could be opened by the fingers of the same hand which is holding the container. Such action is not possible in the types of closures and valves of which the two mentioned patents are examples.
It is therefore the principal object of the instant invention to provide a dispensing closure for liquid and semi-liquid materials which is adapted to be placed on containers by the use of automatic capping machinery and yet which makes it possible for the ultimate user to open the valve or closure with the fingers of the same hand which is holding the container.
Another object of the present invention is to provide a dispensing closure which is a unitary structure, i.e., is a one-piece construction and thus can be fabricated in molds having a plurality of single cavities, the unitary structure including both the cap portion which is adapted to be placed on the neck of the container and a stopper or plug which is moveable to both "closed" and "open" positions.
It is yet another object of the instant invention to provide a one-piece dispensing closure which readily can be manufactured at high speed and in multi-cavity dies of a molding machine and the integral parts of which can be put in "closed" position by accessory mechanisms in the molding machine thereby eliminating manual assembly or the use of additional assembly machines.
And yet another object of the invention is to provide a unitary dispensing closure which can be produced at high speed in a multi-cavity die of an injection molding machine with the parts thereof in such position relative to each other as to make possible production in that fashion and the parts of which relatively easily can be moved to "closed" position and ejected from the molding machine in condition for direct shipment to the manufacturing user without further assembly or manufacturing steps.